Rename subnet for clarity, pick subnet on client

server/lib/exitNodes/getUniqueSubnetForExitNode.ts

@@ -0,0 +1,41 @@
+import { db, ExitNode, Transaction, sites, clients } from "@server/db";
+import { eq } from "drizzle-orm";
+import config from "@server/lib/config";
+import { findNextAvailableCidr } from "@server/lib/ip";
+import { lockManager } from "#dynamic/lib/lock";
+
+export async function getUniqueSubnetForExitNode(
+    exitNode: ExitNode,
+    trx: Transaction | typeof db = db
+): Promise<string | null> {
+    const lockKey = `subnet-allocation:${exitNode.exitNodeId}`;
+
+    return await lockManager.withLock(
+        lockKey,
+        async () => {
+            const [sitesQuery, clientsQuery] = await Promise.all([
+                trx
+                    .select({ subnet: sites.exitNodeSubnet })
+                    .from(sites)
+                    .where(eq(sites.exitNodeId, exitNode.exitNodeId)),
+                trx
+                    .select({ subnet: clients.exitNodeSubnet })
+                    .from(clients)
+                    .where(eq(clients.exitNodeId, exitNode.exitNodeId))
+            ]);
+
+            const blockSize = config.getRawConfig().gerbil.site_block_size;
+            const subnets = [...sitesQuery, ...clientsQuery]
+                .map((row) => row.subnet)
+                .filter(
+                    (subnet): subnet is string =>
+                        !!subnet &&
+                        /^(\d{1,3}\.){3}\d{1,3}\/\d{1,2}$/.test(subnet)
+                );
+            subnets.push(exitNode.address.replace(/\/\d+$/, `/${blockSize}`));
+
+            return findNextAvailableCidr(subnets, blockSize, exitNode.address);
+        },
+        5000 // 5 second lock TTL - subnet allocation should be quick
+    );
+}

server/lib/exitNodes/index.ts

@@ -3,3 +3,4 @@ export * from "./exitNodeComms";
 export * from "./subnet";
 export * from "./getCurrentExitNodeId";
 export * from "./calculateExitNodeWeight";
+export * from "./getUniqueSubnetForExitNode";

server/lib/rebuildClientAssociations.ts

@@ -966,7 +966,7 @@ export async function updateClientSiteDestinations(
         .where(eq(clientSitesAssociationsCache.clientId, client.clientId));
 
     for (const site of sitesData) {
-        if (!site.sites.subnet) {
+        if (!site.sites.exitNodeSubnet) {
             logger.debug(`Site ${site.sites.siteId} has no subnet, skipping`);
             continue;
         }
@@ -1002,7 +1002,7 @@ export async function updateClientSiteDestinations(
                 sourcePort: parsedEndpoint.port,
                 destinations: [
                     {
-                        destinationIP: site.sites.subnet.split("/")[0],
+                        destinationIP: site.sites.exitNodeSubnet.split("/")[0],
                         destinationPort: site.sites.listenPort || 1 // this satisfies gerbil for now but should be reevaluated
                     }
                 ]
@@ -1010,7 +1010,7 @@ export async function updateClientSiteDestinations(
         } else {
             // add to the existing destinations
             destinations.destinations.push({
-                destinationIP: site.sites.subnet.split("/")[0],
+                destinationIP: site.sites.exitNodeSubnet.split("/")[0],
                 destinationPort: site.sites.listenPort || 1 // this satisfies gerbil for now but should be reevaluated
             });
         }

server/lib/traefik/getTraefikConfig.ts

@@ -87,7 +87,7 @@ export async function getTraefikConfig(
             siteId: sites.siteId,
             siteType: sites.type,
             siteOnline: sites.online,
-            subnet: sites.subnet,
+            subnet: sites.exitNodeSubnet,
             exitNodeId: sites.exitNodeId,
             // Domain cert resolver fields
             domainCertResolver: domains.certResolver,